Fastener driving tool



Jan. 27, 1970 E. J. NOVAK 3,491,932

FASTENER DRIVING TOOL Filed April 21. 19 7 2 Sheets-Sheet 1 Janl 27;1970 E. J. N OVAK FASTENER-DBIVING TOOL 2 Sheets-Shee't .2

' Filed April 31, 1967 a; ff .2.

-III IIIII/IIIIIIIIA Mia/nan 50mm J Nam/z United States Patent 3,491,932FASTENER DRIVING TOOL Edward J. Novak, Franklin Park, Ill., assignor toFastener Corporation, Franklin Park, 111., a corporation of IllinoisFiled Apr. 21, 1967, Ser. No. 632,575 Int. Cl. Bc 1/04, 3/00 US. Cl.227-436 16 Claims ABSTRACT OF THE DISCLOSURE A magazine assembly forfeeding fasteners from a carrier strip into the drive track of a drivingtool, including guideway means for supporting a strip of fasteners formovement toward the drive track, first fastener engaging means movablelaterally with respect to one side of said guideway is provided normallypreventing rearward movement of the fasteners away from the drive track.Second fastener engaging means, movable laterally with respect to anopposite side of the guideway, is provided for advancing the fastenerstoward said drive track. Stop means associated with one of said firstand second fastener engaging means is movable inwardly into the guidewayinto a stop position for preventing further forward advance of thefasteners toward the drive track and means is provided for moving saidsecond fastener engaging means toward and away from said drive track topick up and advance successive fasteners into a position ready to bedriven by the tool.

The present invention relates to fastener driving tools and, moreparticularly, to power driven tools and their magazines for handlingfasteners supplied from carrier strips.

In many power driven fastener driving tools, the fasteners to be drivenare relatively large (for example, 6d or 8d common nails) and thesefasteners are supplied from carrier strips constructed of plasticmaterial and the like to hold a plurality of such fasteners in spacedrelation to the one another. The fastener holding strips may berelatively short in length and hold a number of fasteners (approximately20 to in relatively small fiat packages for insertion into the magazineof the tool, or the strips may be relatively long and flexible forholding a much larger number of fasteners and, in this case, the stripsmay be coiled or rolled into a bundle with only the forward end of thestrip extending into the magazine. In the latter instance, as thefasteners are driven by the tool, the coil or roll is unwound as thefasteners are moved forwardly through the magazine into the drive trackof the tool.

One of the problems associated with power driven tools and magazineassemblies of this type is that of providing means for positivelyfeeding successive fasteners from the strip into the drive track of thetool after a previous fastener has been driven. A closely relatedproblem is that of providing an automatic power driven tool and magazineassociated therewith, which is simple in construction and operation,light in weight, small in size, economical to manufacture, andrelatively foolproof and reliable in operation.

It is an object of the present invention to provide a new and improvedpower driven, fastener driving tool and magazine assembly whicheliminates and corrects the aforementioned problems and which is capableof handling small or relatively large fasteners.

Another object of the present invention is the provision of a new andimproved fastener driving tool and magazine assembly associatedtherewith in which the feeding Patented Jan. 27, 1970 of fasteners fromthe magazine into the drive track of the tool is positively effectedafter the completion of a power stroke of the driver of the tool.

Still another object of the invention is a new and improved fastenerdriving tool and magazine including automatic means for positivelystopping the feeding of fasteners into the tool when the number offasteners remaining in the magazine reaches a selected minimum number.

Another object of the invention is the provision of a new and improvedfastener feeding magazine assembly for use with a power driven, fastenerdriving tool.

Yet another object of the present invention is the provision of a newand improved magazine assembly for a fastener driving tool includingreleasable means operable to permit rearward withdrawal of a fastenerstrip therefrom.

Still another object of the invention is the provision of a new andimproved fastener feeding magazine assembly for automatic feeding offasteners from a carrier strip employing means normally operative toprevent rearward movement or withdrawal of the fastener carrying stripfrom the magazine during feeding operations after insertion of thefastener strip into the magazine.

Yet another object of the invention is the provision of a new andimproved fastener driving tool capable of driving large, headed nailsand including new and improved means for guiding the nails in the drivetrack as they are driven to prevent the nails from cocking or beingdriven at an angle and thereby eliminating or reducing the possibilityof bending the nails while they are driven.

Still another object of the invention is the provision of a new andimproved nail guide means as described above which is effective inguiding many different sizes of nails which are driven by the toolwithout requiring adjustments in the guide means.

These and other objects and advantages of the present invention areaccomplished by the provision of a new and improved power driven toolcapable of driving large, headed nails and including a magazine assemblyfor positively feeding the nails from a carrier strip, one at a time,into the drive track of the tool. The magazine assembly includes a pairof spaced guide rails forming a nail guideway to support the strip ofnails by the nail heads for movement along the guideway toward the drivetrack. A first nail engaging means or pusher is biased laterallyinwardly into engagement with the nails in the guideway from one sidethereof and a second nail engaging or holding means is biased laterallyinwardly into engagement with the nails in the guideway from an oppositeside thereof. Each of the nail engaging means includes structureprojecting into the nail guideway having a plurality of nail engaging,spaced recesses between adjacent teeth, and the teeth include forwardlyfacing, lateral leading edges for engaging the rearward edges of thenails. The teeth also include rearwardly and outwardly extending cammingsurfaces for camming the respective nail engaging means outwardly of theguideway as the nails are advanced forwardly along the guideway towardthe drive track relative to the nail engaging teeth. The pusher means ismovable longitudinally with respect to the guideway toward and away fromthe drive track so that on a forward or feeding stroke, the nailsengaged in the recesses thereof are moved forwardly by the advancingleading edges of the teeth. On rearward movements or return strokes ofthe pusher means, the teeth are cammed laterally the camming surfacesthereon against the nails and, after the pusher is moved far enoughrearwardly, the teeth are able to move inwardly again behind the nextsucceeding group of nails in the strip until the nails are seated in therecesses. During the rearward movement of the pusher means, the nailsare engaged and held within the recesses of the second nail engaging orholding means and are prevented from moving rearwardly along with thepusher means. On a forward feeding stroke, the advancing nails engagethe camming surfaces of the nail holding means and cam the holding meansoutwardly thereby permitting the nails to be moved forwardly in theguideway until the teeth of the holding means are able to move inwardlybehind the next succeeding group of nails in the strip. Operator meansare provided for moving the pusher means on feeding and return strokes,and the operator means is actuated by the tool so that a feeding strokeis accomplished after each driving stroke of the driver.

The magazine assembly may also include a guide means having a forwardtip or end extending to the rear face of the drive track to help guidethe lower end of the nail into the lower end of the drive track toprevent the nail from becoming cocked or jammed in the drive trackduring a driving stroke. The forward tip of the guide means normallyextends upwardly above the lower ends of the fastener centered in thedrive track and is momentarily depressed downwardly as each successivefastener is moved into the drive track from the magazine.

For a better understanding of the invention, reference should be had tothe following detailed description taken in conjunction with thedrawings, in which:

FIG. 1 is a fragmentary side elevational view of a magazine assembly andtool constructed in accordance with the present invention with portionsbroken away to show interior components thereof;

'FIG. 2 is a sectional view taken substantially along line 22 of FIG. 1;

FIG. 3 is a sectional view taken substantially along line 3-3 of FIG. 2;

FIG. 4 is a transverse sectional view taken substantially along line 44of FIG. 1 and illustrating the internal components of the assembly inone operating position;

FIG. 5 is a transverse sectional view similar to FIG. 4 but illustratingthe components in another operating position;

FIG. 6 is a fragmentary sectional view of the pusher and holding meansof the magazine assembly taken substantially along line 66 of FIG. 1 andillustrating these components in one operating position;

FIG. 7 is a view similar to FIG. 6 but illustrating the pusher andholding means of the magazine assembly in another operating position;and

FIG. 8 is also a view similar to FIG. 6 but illustrating the pusher andholding means of the magazine assembly in yet another operatingposition.

Referring now, more particularly, to the drawings, therein isillustrated a new and improved power driven fastener driving tool,indicated generally by the numeral 10, and constructed in accordancewith the features of the present invention. Preferably, the tool isoperated by compressed air; however, other means, such as electricalenergy, can also be utilized to power the tool for driving fasteners.The tool 10 illustrated is of the type operated by compressed air andincludes a pneumatic motor mechanism indicated generally as 12 (FIG. 1)for reciprocally moving a driver 14 on a downward power or drivingstroke and subsequently on an upward or return stroke. The driver 14 isslidably disposed in a drive track 16 which is formed in a nosepiece 18(FIGS. 1, 2, and 3), and the nosepiece 18 depends downwardly fro-m thehead portion of the main body or housing 20 which encloses the pneumaticmotor mechanism 12. The major portion of the tool housing 20 is notshown in the drawings and can be of a known type, such as that shown inUnited States Patent No. 3,253,760, which is assigned to the sameassignee as the present invention. A power or driving stroke of thedriver 14 is initiated by depression of a trigger valve (not shown)which provides for the entry of pressurized air into the upper end of aslida'ble cylinder or sleeve 22 (FIG. 1) comprising part of the motormechanism 12 of the tool. A piston (not shown) also comprising a part ofthe motor mechanism is slidably mounted in the sliding sleeve orcylinder 22 and is connected to the upper end of the driver 14. During apower stroke, the sleeve 22 is moved downwardly to open the upper endthereof to compressed fluid which drives the piston and driver 14rapidly downward. After completion of a power stroke, the sleeve 22moves upwardly and pressurized fluid within the sleeve moves the pistonand driver upwardly on a return stroke, as more completely described inthe aforementioned United States patent. Movement of the sleeve 22 iseffected by the pressurization or evacuation of an annular chamber 26formed in the tool housing around the lower end of the sleeve and thesleeve includes an outwardly extending flange 22a which forms an upperwall portion of the chamber 26.

The nails to be driven by the tool 10 are mounted on carrier strips 30formed of flexible plastic material (FIGS. 1 and 3) which extendtransversely across the shanks of the nails and hold the nails in spacedparallel relation to one another. As illustrated, the nails may compriselarge, round-headed nails 32 (for example, 8d common nails) and thestrips 30 are arranged in parallel relation with each other to maintaina selected spacing between adjacent nail shanks 32b somewhat greaterthan the shank diameter thereof. As best shown in FIG. 2, the nails 32are arranged with their heads 32a spaced apart and vertically stacked inrelation to one another and, accordingly, the strips 30 extend acrossthe nail shanks 32b at angles of degrees or somewhat less, measuredclockwise from the nail shanks. The strips 30 are constructed of plasticmaterial and the like, in accordance generally with strips of the typeshown and described in United States Patent No. 3,212,632, dated Oct.19, 1965, and in United States Patent No, 3,261,526, dated July 19,1966. In the latter instance, wherein the strips are relatively long,they may be coiled or rolled into a bundle which is uncoiled as thenails are driven by the tool. In the former instance, the nails may beassembled in relatively small flat packages, wherein the carrier stripsare fabricated in appropriate lengths designed to hold a selected numberof the nails 32. Paper or other backing material 30a may be applied tothe outer side faces of the plastic strip material to add strength andfacilitate easy handling and sliding of the strips into and alongmagazine wall surfaces and the like.

In order to support the nails and feed them into the drive track 16, amagazine assembly, generally indicated as 34 (FIGS. 1 and 2), isconnected to the nosepiece 18 of the tool in communication with thedrive track 16 through a rearwardly opening mouth or entrance 16a,conforming a substantially in cross section to the shape or outline ofthe nails. The entrance slot 16a is aligned with the longitudinal axisor vertical center plane of the magazine between a pair of rearwardlyextending, parallel, inner sidewalls or guide rails 38a and 38b defininga nail guideway 36. The heads of nails are supported on the upper edgesof the inner sidewalls for sliding movement along the guideway 36 towardthe drive track 16. The inner sidewalls 38a and 38b are supported from apair of outer, magazine sidewalls 40a and 40b by means of a plurality ofshort transversely extending cap screws 42 which extend inwardly intothe axial, threaded 'bores of aligned spacer sleeves 43, or bosses,which are disposed between pairs of adjacent inner and outer magazinesidewalls and are preferably welded or otherwise affixed permanently tothe outer surfaces of the inner sidewalls 38a and 38b.

The magazine assembly 34, as a whole, is connected to and supported fromthe nosepiece 18 by a pair of forwardly extending mounting brackets 44which are secured to the respective outer sidewalls 40a and 40b by spotwelding or the like. The forward portions of the supporting brackets 44and similarly shaped, forwardly projecting tabs or lugs 41 (FIG. 2) ofthe respective outer sidewalls 40a and 40b are welded together and areseated within appropriate recesses or ways 18a (FIG. 1) formed in thenarrow sides of the nosepiece. The magazine assembly 34 is readilydisconnected from the nosepiece 18 and to this end, the nosepiece isprovided with a pair of laterally, outwardly extending, threaded studs46 which project through forwardly opening, aligned slots 44a and 41aformed in the brackets 44 and projecting lugs 41, respectively.Self-centering nuts 48 are threaded onto the studs 46 to bear inwardlyagainst the brackets 44 and hold the magazine assembly 34 in place. Thenuts include annular, conical, centering surfaces 48a on the inner facesthereof which seat within similarly shaped, concave beveled,frustoconical portions formed in the outer surface of the brackets 44adjacent the inner or closed ends of the slots 44a therein. Accordingly,when the nuts 48 are tightened, the brackets 44 and projecting lugs 41are firmly held in the ways 18a of the nosepiece and, in addition, exactlongitudinal and lateral positioning, of the forward end of the magazineassembly 34 in relation to the nosepiece is established. Once the nutsare loosened, the magazine assembly 34 can be withdrawn rearwardly andcompletely disconnected from the nosepiece 18.

In order to accurately align the forward end of the magazine assembly 34with the entrance opening 16a, the nosepiece is formed with a recess 18b(FIG. 1) opening toward a planar back face 180 thereof. The innersidewalls 38a and 38b are formed with short, forwardly extendingprojections 39 at the forward ends thereof, which extend into the recess18b and maintain the magazine guideway 36 in proper vertical alignmentwith respect to the entrance opening 160 of the drive track.

The spacing between the outer walls 40a and 40b at the forward end ofthe magazine assembly 34 is maintained by the brackets 44 which areseated in the ways 18a on opposite sides of the nosepiece 18, and thenosepiece 18 thus maintains the correct spacing between the opposite,inner sidewalls 38a and 38b so that the nails 32 slide easily along theguideway 36 between the inner sidewalls. The spacing between the outerwalls 40a and 40b at the rearward end of the magazine assembly ismaintained by a pair of spacing bolts 50, the upper of which carries atubular spacer 52 disposed between the outer sidewalls. In addition tothe spacing bushings 43 and screws 42, minimum spacing between the innersidewalls 38a and 38b and the respective adjacent outer walls 40a and40b is insured by a pair of lower, outwardly extending flanges 35 formedon the respective inner sidewalls (FIGS. 4 and 5) and by a pair of lowerspacing brackets 37 of L-shaped cross section having outwardlyextendingly flanges 37a and upright flanges 37b spot welded to the outersurfaces of the inner sidewalls. The magazine assembly 34 is constructedto be long enough to hold at least one or more assembled packages ofnails and, if needed, additional spacers can be used to maintain thespacing between the outer sidewalls along the length of the magazinewhen the magazine is longer.

A strip of nails 32 is inserted into the guideway 36 from the rear endof the magazine and is moved forwardly until the first or lead nail ofthe strip is positioned in the drive track 16. As nails are driven bythe driver 18 of the tool, the strip is moved forward in successiveincrements to position the succeeding nail at the forward end of thestrip into the drive track.

In order to feed nails forwardly along the guideway 36 and preventrearward movement thereof, the magazine assembly 34 includes a pair ofnail engaging members 54 and 56 disposed on opposite sides of the nailguideway 36 between respective adjacent pairs of inner and outersidewalls 38a and 40a and 38b and 40b of the magazine. The members 54and 56 are L-shaped in transverse cross section and include laterallyinwardly projecting upper flanges 54a and 56a, respectively, anddownwardly extending sides or bodies 54b and 56b. The inner sidewall 38ais provided with a longitudinally extending slot 57 spaced below theupper edge thereof to permit the upper flange 54a to project inwardlyinto the guideway 36. The inner sidewall 38b is provided with a pair ofspaced, longitudinally extending slots 58 and 59 for permitting portionsof the upper flange 56a to project inwardly into the guideway 36 fromthe opposite side, as best shown in FIGS. 6, 7, and 8.

The member 56 serves as a holding or latching dog against rearwardmovement of the nails and is mounted between the inner wall 38b andouter wall 40b in a manner that permits the upper nail engaging flange56a to move laterally inwardly and outwardly with respect to theguideway 36. To this end, the downwardly extending body 56b is formedwith a pair of spaced openings 61 (FIG. 3) to receive a pair of mountingpins 62 which project outwardly from the inner sidewall 38b to supportthe member 56. The openings 61 are slightly larger in diameter than thepins 62 to permit pivotal movement of the member 56 about an axislongitudinally parallel with the guideway 36 and extending transverselythrough the mounting pins. The body 56b also includes a pair oflaterally inwardly projecting ears 63 extending normal to the body andpositioned along opposite edges thereof adjacent the pins 62 (FIG. 3).These ears are rounded on their ends (FIG. 2) and the rounded surfacesbear inwardly against the outer surface of the inner magazine wall 38band thereby maintain the lower end of the body 56b in outwardly spacedrelation from the adjacent wall 38b, as shown in FIGS. 4 and 5. A largecentral cutout or opening 64 is provided in the body 56b to accommodatea biasing spring 65 which is mounted in the opening and normally biasesthe upper flange 56a of the member laterally inwardly into the guideway36, through the openings 58 and 59'. The spring 65 is constructed from acontinuous length of spring steel wire formed in a generally U-shapedconfiguration and including an upper bight or crown portion 65a, a pairof downwardly extending legs 65b having intergrally formed coiledportions 650 at their lower ends, and a pair of upwardly extending outerlegs 65d joined with the coiled portions. The outer legs 65d of thespring extend upwardly along opposite side edges of the opening 64, andthe upper ends thereof bear inwardly against the upper portion of thebody 56b tending to force the upper flange 56a of the member 56laterally inwardly into the guideway 36. The coiled portions 650 arecentered and mounted on a pair of lugs 66 projecting inwardly toward thecentral portion of the body 56b from opposite the side edges of theopening 64. The bight portion 65a of the spring exerts pressurelaterally outwardly with respect to the guideway 36 against an uppershouldered or offset portion 67a of a Z-shaped bracket 67 having a lowerleg 67b spot welded or otherwise secured to the outer surface of thesidewall 38b.

The biasing spring 65 thus exerts a biasing force on the member 56,urging the upper, nail engaging flange 56a thereof laterally inwardlyinto the guideway 36. The member 56 is mounted so that it will pivotfreely about a lower axis longitudinally parallel with the guideway 36and extending through the lower portion of the body 56b adjacent theears 63, lugs 66, and mounting pins 62. Because of the manner in whichthe holding member 56 is mounted on the spaced pins 62, the membercannot move longitudinally with respect to the guideway 36 and,accordingly, the member 56 functions as a holding or latching membernormally preventing rearward movement of the nails, once they have beeninserted into the guideway 36 of the magazine assembly.

In order that the member 56 may engagingly hold the nails 32 in thecarrier strip and prevent them from moving rearwardly along the guideway36, the upper nail engaging flange 56a is formed to include a firstsegment or portion 59a (FIG, 3) which is movable in and through therearwardly positioned slot 59 in the sidewall 38b. The segment 59aincludes a plurality of longitudinally spaced nail engaging teeth 68along the edge which faces the guideway 36, as best shown in FIGS. 6, 7,and 8. Each of the teeth includes a laterally extending, forwardlyfacing leading edge 68a, generally perpendicular to the guideway 36, forengagement against rearwardly facing portions of the nail shanks 32b.Each tooth is formed with a rearwardly and outwardly sloping, trailingedge or camming surface 68b, and the edges 68a and 68b of adjacent teethform the edge portions or opposite walls of a plurality of nail shankreceiving recesses 69 between each pair of adjacent teeth. As the nailsare moved forwardly along the guideway 36, the shanks 32b engage thecamming edges 68b and move the upper flange 56a of the holding member 56laterally outward against the biasing force of the spring 65. When nailshanks 32b have advanced forwardly of the leading edges 68a of theteeth, the spring 65 is then free to move the flange 56a laterallyinwardly into the position shown in FIGS. 6 and 7 wherein the nailshanks are seated in the recesses 69. In this position, the lateralleading edges 68a of the teeth prevent rearward movement of the nails.As the nails are advanced forwardly during each successive feedingstroke, each nail moves to the next adjacent forward recess 69. When thelast nail in a strip has advanced forwardly of the forwardmost tooth 68,the bias spring 65 is then free to move the upper flange 56a of themember 56 further inwardly into the guideway to a stopping position, asshown in FIG. 8.

Immediately ahead of the forwardmost tooth 68, the flange 56a is formedwith a large recess 70 which is deep enough to accommodate at least oneor more nails 32 without interference, and when the last nail in thestrip has been advanced past the forwardmost tooth 68 into positionadjacent the recess 70, there is no engagement between any of the nailshanks 32b and the flange section 59a which can prevent movement of themember 56 from its normal operating position (FIGS. 6 and 7) to the stopposition illustrated in FIG. 8. The flange 56a includes a laterallyinwardly projecting, forwardly positioned stop tooth or dog 71 which hasa laterally extending, rearwardly facing edge 71a, defining the forwardend of the recess 70. When the member 56 is in the stopping position, asshown in FIG. 8, the edge 71a engages any of the nails present in therecess 70 and prevents their further forward travel along the guideway.When forward travel of the nail strip is stopped in this manner, thetool operator is alerted that the nail supply in the magazine assemblyis getting low and a new strip of nails should be inserted into theguideway 36 from the rear end thereof. During normal operations, whennails are in engagement within the recesses 69 between adjacent teeth68, the stop tooth 71 is outwardly of the guideway 36 (FIGS. and 6) anddoes not interfere with forward movement of the nails.

Upon insertion of a nail strip from the rear end of the magazine andsubsequent forward movement of the nails toward the drive track 16,engagement between the nails and the camming surfaces 68b of the teethcauses the flange 56a to move laterally outwardly with respect to theguideway 36 and out of stop position (FIG. 8) to the normal operatingpositions shown in FIGS. 6 and 7. From the foregoing description, it isclear that when the holding member 56 is in a normal operating position,forward feeding of the nails 32 into successive forward positions alongthe guideway 36 is permitted either during normal feeding strokes orupon initial insertion of a nail strip into the guideway and because oflaterally extending leading edges 68a of the teeth rearward travel ofthe nails is prevented.

When the number of nails in the magazine reaches a selected minimumnumber and the last or rearwardmost nail in the strip is adjacent therecess 70, the member 56 is moved by the spring 65 laterally inward intothe stop position (FIG. 8), and the stop tooth 71 prevents furtherforward feeding of the nails until the supply is replenished byinsertion of another strip of nails.

In the illustrated embodiment, when the last nail in a package or stripof nails engages the stop tooth 71, there are still eight nailsremaining in the strip and it has been found in practice that it isdesirable that a selected minimum number of around eight is suitable.For example, when there is only one nail remaining in the strip in themagazine, there would be nothing to keep the nail from droppingdownwardly as soon as it is advanced into the drive track, and if onlytwo or three nails remain in the strip when the stop tooth 71 is engagedby the last nail it is sometimes possible for the strip to become cockedor jammed in the magazine because of the rearward nails in the stripmoving upwardly and the forward nail is driven by the impact of thedriver. Accordingly, it has been found that a selected minimum number ofeight provides good stability and overcomes the above difficultiesbecause of the added weight of the additional nails.

The nail engaging pusher member 54 is somewhat similar in appearance tothe holding member 56 and performs the function of advancing the nails32 on successive feeding strokes along the guideway 36. The member 54 ismounted on the magazine so that the upper flange 54a will move laterallyinwardly and outwardly with respect to the guideway 36 and, in addition,the flange is movable back and forth longitudinally of the guidewaytoward and away from the drive track. The flange 54a normally extendsinto the guideway 36 through the longitudinal slot 57 in the sidewall38a and the body 54b is mounted between the walls 38a and 40a on asingle mounting pin 72 which projects outwardly from the inner wall 38aand is secured thereto in a suitable fashion, such as by spot welding.The pin 72 terminates short of the outer wall 40a (FIGS. 4 and 5) and isprovided with an annular recess 72a closely adjacent to its outer end inorder to receive a removable retaining or C-ring or washer 74 forholding a coiled biasing spring 76 interposed between the outer surfaceof the body 54b and the washer. The spring 76 exerts an inward biasingforce against the body 54b forcing the upper flange 54a laterallyinwardly into the guideway 36 through the slot 57. The pin 72 issomewhat smaller in diameter than the diameter of the opening in thebody 54b through which the pin projects and, accordingly, the member 54is pivotable about the pin. When the member 54 pivots about the axis ofpin 72 in a counterclockwise direction, as viewed in FIG. 1, the upperflange 54a moves forwardly toward the drive track 16 and, in doing so,accomplishes a forward feeding stroke to move the nails 32 forwardly. Inorder to move the member 54 about the pin as described, the body 54bincludes a forwardly extending actuating arm 540 having a laterallyoutwardly extending tab 54d adjacent the upper edge of the arm at theouter end thereof. Downward force against the tab 54d causes the upperflange 54a to move on a forward or nail advancing feed stroke, whileupward movement of the arm tab permits the member 54 to pivot in aclockwise direction (FIG. 4) and a return stroke toward the rear of themagazine is accomplished. The slot 57 is long enough and wide enough topermit forward and rearward movement of the flange 54a withoutinterference.

The flange 54a includes a plurality of spaced, laterally, inwardlydirected teeth 78 which are spaced apart by a distance equal to thespacing between the nails 32 and the spacing between the teeth 68 in theholding member 56. Each tooth 78 includes a laterally extending,forwardly facing, advancing or leading edge 78a and a rearwardly andoutwardly extending trailing edge or camming surface 78b. Fastenerreceiving recesses 79 are defined between adjacent teeth and theserecesses are concavely rounded, as shown, in order to better receive andhold the nails 32. The leading edges 78a of the teeth are somewhatconcave, as shown, to reduce the possibility of disengagement betweenthe teeth and the nail shanks 32b during a feeding stroke.

Upon forward movement of the teeth 78 on a feeding stroke, 'the leadingedges 78a engage rearwardly facing portions of the nail shanks 32b andadvance the engaged nails forwardly until they are seated in the nextsucceeding recesses 69 of the holding member 56. Upon rearward travel ofthe teeth 78 on a return stroke, the camming or trailing edges 7 8bengage the nail shanks which are held against rearward travel by themember 56, as previously described, and camming action takes placebetween the edges 78b and the nail shanks forcing the upper flange 54aof the pusher laterally outwardly against the biasing force of thespring 76. At the completion of a rearward stroke, the leading edges 68aof the teeth are positioned rearwardly of the nails in the strip held bythe holding member 56 and the flange 54a moves laterally inwardlybecause of the force exerted by the spring 76.

The nail shanks 32b are then seated in the recesses 79 and as thefeeding stroke proceeds the nails are advanced forwardly along theguideway 36 until seated in the next succeeding recesses 69 in theholding member 56. At the end of each feeding stroke a new nail at theforward end of the strip is positioned in the drive track 16 inpreparation for a driving stroke of the driver 14. The flanges 54a and56a of the pusher and holding members, respectively, are spacedvertically from one another to preclude interference during feedingoperations and from the foregoing description it should be noted that ona feeding stroke the pusher flange 54a moves longitudinally forwardwhile the holding member flange 56a is cammed laterally outward. On areturn stroke the holding member flange 56a is stationary while thepusher flange 54a moves rearwardly and is cammed laterally outwardly.The two members 54 and 56 thus cooperate to insure positive feeding ofsuccessive nails into the drive track and normally prevent the rearwardmovement of the nails away from the drive track.

In order to permit the nails or strips thereof to be withdrawn orremoved from the rear end of the magazine 34, a pair of manual releasebuttons 80' and 82 are mounted on the respective outer magazine walls40a and 40b. The release buttons 80 and 82 are identical and eachincludes an enlarged buttonlike head at the outer end and an integralshank which projects inwardly through an opening in the adjacent outersidewall. The inner ends of the shanks are adapted to engage the lowerbody portions of the respective members 54 and 56 when the buttons aredepressed and the shanks are mounted for sliding movement with a pair oftubular bosses 84 which are force fitted into the openings provided inthe respective sidewalls 40a and 40b, as best shown in FIGS. 4 and 5.The shanks are formed with annular recesses adjacent their inner endsfor receiving retaining washers 86 which prevent outward withdrawal ofthe buttons through the bosses 84 (FIG. 4). The inner end of the releasebutton 80 is adapted to engage a downwardly extending tab or projection54a on the pusher member 54, and when the button is forced inwardlyagainst the projection 542, the upper flange 54a is moved laterallyoutwardly with respect to the guideway 36 until the teeth 78 are clearof the nails in the guideway and present no interference to rearwardwithdrawal of the nails. The inner end of the release button 82 isadapted to engage a lower, downwardly projecting tab 56c (FIGS. 4 and onthe holding member 56 to earn the upper flange 56a and teeth 68 thereoflaterally outwardly of the guideway 36 until clear of the nails.Accordingly, when the release buttons 80 and 82 are both depressed by anoperator, the nails can be withdrawn rearwardly from the guideway 36without interference, and when the buttons are then released, the biassprings 65 and 76 cause the members 54 and 56 to return to their normaloperating positions, as previously described.

In order to actuate the pusher member 54 to feed successive nails intothe drive track 16 after a driving stroke has been completed, the tool10 includes an actuator assembly 88 which is preferably mounted on thebody of the tool for interconnection with the actuating arm or operator540 of the pusher member. The actuator assembly 88 includes a chamber 90formed in the tool body, and a tubular sleeve 92 having an aperturedlower end is inserted into the chamber to form a cylinder for slidingmovements of a piston member 96 mounted thereon. The upper end of thechamber is in direct communication with the annular chamber 26 aroundthe sleeve 22 by means of a transverse connecting passage 94 and,accordingly, the upper end of the chamber 90 is maintained at a pressureequal to that in the chamber 26. The piston 96 includes a head 96a and asmaller diameter, downwardly extending stern 96b which projects throughthe lower, internally flanged open end of the sleeve 92. The stem 96b isformed with one or more elongated slots 960 to permit atmospheric air toenter the lower end of the sleeve beneath the piston head 96a. The lowerend of the piston member 96 is connected to a roller support bracket 98having a roller 102 mounted thereon for engagement against the tab 540!on the arm 540 of the pusher member 54. The roller support bracket 98 isslidable between an upper position (FIG. 1, dotted lines) and a lowerpositiontFlG. 1, full lines) and is guided for vertical reciprocatingmovement between these positions by a fixed bracket secured to the outersurface of the magazine wall 38a and formed to include an outwardlyextending upper guide flange 100a having a slot therein through whichthe support bracket 98 is guided. Normally, the pusher member 54 ismaintained in a rearward position (dotted lines, FIG. 1) by means of abiasing spring 104 having an elongated, forwardly extending leg 104abearing upwardly against the tab 54d, a coiled portion 10411 mounted ona lower rear spacing sleeve 43, and a short leg 1040 which bearsdownwardly against the bottom flange 35 between the magazine walls 38aand 40a. The spring 104 exerts a clockwise biasing force on the member54 about its mounting pin 72 and, accordingly, forces the piston 96upwardly in the sleeve 92 when the air pressure above the piston isreduced sufliciently. When a power stroke of the driver 14 is initiatedthe annular chamber 26 is vented to the atmosphere and, accordingly, theroller assembly moves upwardly under the force of the spring 104. Whenthis occurs, the pusher 54 moves in a clockwise direction from theposition shown in solid lines in FIG. 1 to the position shown in dottedlines therein on a return stroke. After a driving stroke is completed,the chamber 26 is again filled with pressurized fluid which flowsthrough the pas sage 94 into the upper end of the sleeve 92 forcing thepiston 96 downwardly. When this occurs, the pusher member 54 pivots in acounterclockwise direction against the spring 104 on a feeding strokeand moves the next nail 32 into the drive track 16. After the next powerstroke of the driver 14, the nail feeding cycle is repeated and the1pusher member 54 feeds another nail into the drive tr-ac In accordancewith another aspect of the invention, the tool 10 includes a nailguiding mechanism to prevent the lower end of the nail being driven fromcocking to the rear far enough so that it will not pass smoothly outthrough the lower end of the drive track as it is driven. To this end, alongitudinally extending nail guiding finger is provided and the fingeris pivotally mounted at its rearward end on the lower and rearwardspacer bolt 50 between the outer magazine sidewalls 40a and 40brearwardly remote from the drive track. The rear end of the finger 110is provided with a laterally extending tubular sleeve 112 which isjournaled on the bolt 50 and which additionally serves as a spacerbetween the outer sidewalls. The finger is biased in a clockwisedirection about the bolt 50 by means of a spring 114 having a coiledbody mounted on the sleeve 112 and a forwardly extending spring finger114a which is engaged in a slot 110a formed in the finger (FIGS. 3, 4,and 5). The spring also includes an upwardly extending leg 114b whichprotrudes upwardly to bear against the outer end of the bottom wall orflange 35 of the magazine.

The forward tip portion of the guide finger 110 includes an outer endsurface 11% which is positioned to be even with the rearward wallportion of the drive track 16 and includes a forwardly upwardly slopingupper edge surface 110c intersecting the surface 11012 at a point 110d.In a normal position of the finger 110, the point 110d is above thelower end of the nail 32 positioned in the drive track (as best shown inFIG. 3) and, accordingly, the end surface 11011 prevents the lower endof the nail from cocking rearwardly far enough to move out of the drivetrack and jamming during a driving stroke. The spring 114 biases theguide finger 110 in a clockwise direction so that an upper edge 110athereof rearwardly of the tip portion is always in contact against thelower end of the forwardmost nail in the magazine and, as this nail isfed forwardly from the magazine into the drive track, the upwardlysloping surface 1100 of the finger is cammed downwardly momentarilyuntil the nail is forwardly clear of the end surface 11011 and inposition in the drive track 16. Because the finger 110 is pivotedrearwardly remote from the drive track and is relatively long, nails ofdifferent length can be used in the tool without jamming problemsbecause the forward guiding end surface 110]) of the finger, whilemovable on a circular arc, is always closely adjacent the rearwardportion of the drive track wall. The nail guiding mechanism of the tooleliminates a common problem occurring in a tool capable of driving largeround headed nails, and effectively prevents jamming of the nails in thelower end of the drive track because of rearward cocking of the lowerend of the nails during a driving stroke.

The present invention thus provides a new and improved fastener drivingtool and magazine assembly capable of automatically driving large nailsand the like supplied from a carrier strip. Nail feeding action of themagazine is swift and positive after each driving stroke of the driver.In addition, the magazine indicates to the operator when the supply offasteners is getting low and permits the easy insertion of a new supply.Manual release means are provided for permitting removal of thefasteners from the magazine.

While there has been illustrated and described a single embodiment ofthe present invention, it will be apparent that various changes andmodifications thereof will occur to those skilled in the art. It isintended in the appended claims to cover all such changes andmodifications as fall within the true spirit and scope of the presentinvention.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. A magazine assembly for feeding fasteners from a carrier strip intothe drive track of a driving tool, comprising guideway means forsupporting a strip of fasteners from movement toward said drive track,first fastener engaging means movable laterally with respect to saidguideway from one side thereof for engagement with said fasteners,second fastener engaging means movable laterally with respect to saidguideway from an opposite side thereof for engagement with saidfasteners, said first engaging means including structure adapted toproject inwardly into said guideway and engage said fasteners tonormally prevent rearward movement thereof, said second engaging meansincluding structure adapted to project into said guideway for engagementwith fasteners in said strip and movable toward and away from said drivetrack for 'moving said fasteners toward said drive track, stop meansmovable laterally inwardly into a stop position in said guideway withone of said first and second fastener engaging means for engagingfasteners in said guideway to prevent further longitudinal movement ofsaid fasteners toward said drive track, and means for moving said secondengaging means towards and away from said drive track to advancesuccessive fasteners into said drive track.

2. The magazine assembly of claim 1 including manual means on oppositesides of said guideway for moving said inwardly projecting structuresoutwardly of said guideway to permit rearward movement of said fastenerstherein.

3. The magazine assembly of claim 1 wherein said first and secondfastener engaging means are mounted for pivotal movement about axesextending longitudinally of said guideway.

4. The magazine assembly of claim 3 wherein said inwardly projectingstructure of said second engaging means reciprocally is movablelongitudinally of said guideway and said inwardly projecting structureof said first fastener engaging means is fixed against movementlongitudinally of said guideway.

5. The magazine assembly of claim 1 wherein said stop means is movablelaterally with respect to said guideway between a first position clearof said guideway and said stop position wherein said guideway is blockedagainst forward movement of said fasteners therein.

6. In a fastener driving tool including a magazine for holding a supplyof fasteners and advancing them into a drive track, said magazineincluding guideway means for supporting said fasteners, pusher meansmovable toward and away from said drive track for advancing fastenersalong said guideway, holding means independent of said pusher measurefor normally preventing rearward movement of said fasteners in saidguideway, lateral stop means movable into and out of said guideway meansfor blocking the advancement of fasteners therein, said stop meansincluding means responsive to the absence of fasteners in a selectedposition in said guideway means to permit movement of said stop meansinto a stopping position in said guideway means and means on said toolfor reciprocating said pusher means toward and away from said drivetrack.

7. The tool of claim 6 wherein said pusher means is pivotally mounted onan axis transverse with respect to said guideway means and includesfastener engaging means normally projecting into said guideway means andreciprocally movable toward and away from said drive track to advancefasteners toward said drive track.

8. The tool of claim 7 wherein said holding means is pivotally mountedalong an axis parallel with said guideway means and fixed againstlongitudinal movement with respect thereto, said holding means includingfastener engaging means movable laterally into and out of engagementwith the fasteners for normally preventing rearward movement thereof.

9. In a power driven tool for driving fasteners of the type includingenlarged heads at the upper end of depending shanks having smallertransverse dimensions than said heads, comprising a drive trackdimensioned to accommodate said heads as the fasteners are driventherefrom, magazine means communicating with a rearward wall portion ofsaid drive track for feeding successive fasteners forwardly into saiddrive track to be driven, movable shank guiding means having a guidingsurface closely adjacent a wall surface of said drive track for guidingengagement against a lower portion of the shank of a fastener positionedin said guideway, said shank guiding surface normally extending upwardlyabove the lower end of a fastener in said drive track and movabledownwardly therefrom as successive fasteners are advanced forwardly fromsaid magazine means into said drive track.

10. The tool of claim 9 wherein said shank guiding means comprises anelongated finger having said gliding surface at the forward end and arearward end pivotally mounted on said tool remote from said drivetrack.

11. The tool of claim 10 including means normally biasing said fingerupwardly toward engagement with the lower ends of fasteners in saidmagazine means.

12. The tool of claim 11 wherein said finger includes a sloping camsurface thereon engageable with the lower end of a fastener nextadjacent said drive track for pivoting said finger away from the lowerends of successive nails in said magazine each time a nail is advancedinto said drive track.

13. The magazine assembly of claim 5 wherein said inwardly projectingstructure of said first and second fastener engaging means includes aplurality of ratchet teeth arranged in rows and spaced longitudinally ofsaid guideway at an interval substantially equal to the spacing betweensuccessive fasteners in said carrier strip, said stop means comprising aprojection spaced forwardly of a forwardmost ratchet tooth in one row bya distance greater than the spacing between adjacent teeth.

14. The magazine assembly of claim 13 wherein said ratchet teeth in saidone row project inwardly into said guideway beyond said stop meanswhereby, during normal engagement of said teeth in said one row withsaid fasteners, said stop means is spaced outwardly of said guideway.

15. The magazine assembly of claim 14 wherein said stop means and saidone row of ratchet teeth are formed on a common flange portion of saidfirst fastener engaging means, said flange portion extendinglongitudinally of said guideway and generally normal to said fasteners.

14 16. The magazine assembly of claim 15 wherein said flange portion isformed with slot means between said forwardmost tooth and said stopmeans permitting movement of said stop means into said stop positionwhen the rearwardmost fastener in said guideway is forward of saidforwardmost tooth.

References Cited UNITED STATES PATENTS 248,398 10/1881 Brock 2271361,162,678 11/1915 Boden 227136 XR 2,078,064 4/1937 Day 227136 2,923,9372/1960 Laucher 227-135 XR 3,281,046 10/1966 Boulay 227136 XR 3,353,73711/1967 Howard et al. 227136 GRANVILLE Y. CUSTER, 111., Primary Examiner

